LONDON -- The mother of a London teenager who bled to death in a bakery after his throat was cut with a piece of glass said Sunday he probably knew his killer.

Jimmy Mizen, who celebrated his 16th birthday Friday, was remembered during mass at Our Lady of Lourdes, where he was baptized and served as an altar boy, The Guardian reported.

"I have never seen a parish so numb," the Rev. Edward Perera said. "After mass, people usually want to go home quickly. Today nobody moved."

Witnesses said another teenager in the Three Cooks shop in southwest London challenged Mizen to a fight and then, after he refused, broke the shop window with an advertising board. Mizen died in his brother Henry's arms.

No arrest had been made Sunday. His mother, Margaret Mizen, said his family feels no anger toward their son's killer -- probably someone they know.

"I don't feel anger, I feel sorry for the parents," she said. "We've got such lovely memories of Jimmy and they will just have such sorrow about their son. I feel for them, I really do."